Telephone signaling system



UNITED sTAres vPaireiwr Price.

CHAIR/LES W.

KECKLER, OF NEVHLRK, NEVI JERSEY, ASSIGNOR TO TESTERN ELECTRIC COMPANY, INCORPORATED, OF YORK, Nl Y., A CORPORATION F NEW YORK.

1 TELEPHONE siGNeLiNG svsi'rniu.

T o all whom it may concern Be it known that I, CHARLES W. KEGKLEL la citizenrof -theUnited States, residing at VNewark, in the county of Essex andState of New Jersey, have invented certain new and useful Improvements in Telephone Sig-V naling Systems, of which the following is a A full, clear, concise, and exact description.

rlhis invention relatesgenerally tosignaling systems and more particularly' tosuch systems for use in connection .with telephone systems.

The invention has for its objectv to provide in a telephone system, a means for sig-f' naling a 'station'and automatically discon-l 'tinuing that signal; after afpredetermined` Vtime interval.

e This is accomplishedin accordance with i ythis invention Ain its preferred form, by the use cfa combination of'a delayedaction relay whichl is energizedby the operation of a key; another relay, which upon operation'v 'of the `first relay, energizes, establishing other connections whereby it remains ener-V .Y cuit rand establish the talking circuit. ,so

- third relay may be operated by gized while the rst relay releases; `and a third relay which,up0n the operation of the second relay and therelease of .the first relay, `operates to interrupt the-signaling cirsecond winding isV provided on `:the second relay, by which -thevrelayis adapted to be energized from av distant station whereby the the actuation of the firstmentioned keyfto open andiclose the talking circuit without operating; the

. signaling device. v

Y, use. in 'connection with' telephone systems `such as loudV speaker or train despatching systemswhere.attendantsare at the various stationscontinuously. In such systems a' signal -such as a howl in they loud speaking receiver isY desirable because it: attracts vthe A repetition.

tion inits preferred form is shownused vfor The drawing shows ischematic'allyi ailoud.

.speaking system having a central-or master station and afnuinber. of substations; yAll lof the apparatus is ,locatedfat the master sta- :I tion` except that inclosed in' ,dotted .lines which comprises a substation. f'lhe inven- .I y Specification of Letters Patent.

This invention is especiallyadapteddiorv is thenfrom transmitter 9,

f for as will hereinafter bedescribed.

.Vhen the attendant at the master station wishes to communicate lwith station', A, he operates key'a.

ary induction coil windings 2-and 3, right normal Vcontacts of relay 4, `leit contacts of key ato ground. This current is intermit- Current' then' flows from grounded battery through buzzer l, second-y rateiited nee. 13,1921..l 'Applicationinea-December icy-i919. serial No. 345,380. V

tent, dueto the buzzer.` Current also flows?,

from buzzer l, through 'right-outer contacts of key a, normal contacts of key-T,receiver 8, condenser 7 right normal contacts'of"y relaye, left contacts ofkey a to ground. The

howl PI'OdUCed in receiver 8.aetsaglafca11ingf' Signal to station A, 1

of krelay 5', winding'zoi' relay, left lcontacts of key a 'to ground;VV Slow actingi'relay' isf;

groundedv battery throughalternatev contacts of relayrG, leftwiiidingof relayw5,'through Relay 5.' A operates,fbreakingthe normal contactsf'and leftrcontacts of key ato ground;

opening the circuit through relayv winding 6 and normalwposition.: Relay; 1 5 remains 'venergizedhowever, as current is suppliedthrough the iight alternate contact to ,theleftwvinding of -relay 5. Current then'iiowsthrough nor/mall contacts of'rclay -6"left alternate contacts of relay 5, windings of relay 4f, left v v t from I v,grounded battery through normalr 'contacts the armature oi. relay (5v-assumes its l contacts of key A toground.- Relay efoperi ates, opening the buzzer circuit-atjthe right normal contacts of relay 4.' r

VUpon operation of rel y f1, is suppliedto the transmitter 9,-'through retarda- .r tion coillO, transmitter 9alternate contacts y of relay 4, left contacts of key ato ground.

kthe talking current oscillations alternate contact relay 4, letcontacts keya', ground, primary The path of windingo12 ofthe induction coil, condenser;v 5

32, to transmitter-9.

lheinduced current ing 12 iows from n secondaryrwinding .1 3 through left, winding of mechanical amplifier l1 backto secondary winding 13."

windf- 'movable central electrode of the amplifier 11, through the right winding of amplifier 11, retardation coil 14, right alternate contact of relay 4, left contact key a to ground.

The central electrode of amplifier 11 vibrates under the influence exerted on the core by the left winding of the amplifier and produces corresponding variations in prilmary windings 15 and 16.

vInduced -secondary current flows from :wind-ing 2 through right alternate contacts of Vkey a, normal lcontacts of key T, re-

ceiver 8, condenser 7 winding 3, to winding 2. Thus the communication at the transmitter 9 is heard at the receiver 8.

'When the operator is talking at the master -stationkey T of the substation is kept normal and the circuit of the transmitter 30 is open. However, when the operator at sta- -tion A wishes to talk he operates key T and key a is returned to its normal position.

`Battery current is then fed through the right windin of relay 5, the upper left contactsof key to ground. Relay 5 remains 'operated and relay 4 releases due to the opening of the circuit at left contacts of atterycurrent is supplied to ltransmitter 30 vthrough retardation coil 21, transmitter r30, ylower left contacts of key'T, to ground.

The oscillations in the talking current follow the path, transmitter 30, lower left contacts vkeyjT, ground, primary winding 19, con# denser 20 to transmitter 30. Secondaryv in`- duced current oscillations follow the path from secondary winding 18, vthrough right Vwinding of mechanical amplifier 17 `to secondary winding 18.

As'in the case of amplifier 11, amplifier 17 'is supplied with current between primary windings23 and 24, through the outer electrodes, granular carbon elements and central `vibrating ,electrode and left winding of amplifier 17, retarc'lation coil 22, upper left contacts of key T to ground. Osci'llations,

jin'duced in the secondary windings 25 and 26 bythe amplified alternations, flow-through secondary 261eft contact of relay 4 and re- Qsistance 27, receiver 2 8, secondary 2,5,back to secondary `26. Thus the conversation at -transmitte'r 30 is reproduced at receiver 28.

IIffboth keys, 'a and T, are operated at once, relay 4 -is 'operated as before described. and 'left contact of relay 4 is opened. The oscillations in receiver 28 are then reduced by :having to pass 'through high resistance27. Y

, This prevents singing in the system which vtransmitter 9.

-niight be produced by thereceiver 28 on the To produce a similar effect at stationvAv, reslstance 3.1 is used, and the pathy of the secondary induced current is changed asV follows: Through secondary 2, resistance 31, alternate right contacts ofv key T, receiver 8, condenser 7, secondary 3 to secondary 2.

When a call originates Aat station A, key R is first operated. Battery Vcurrent then flows through the buzzer 1, contacts of key R to ground, giving the master station the calling signal. yKey T should then beoperatedand the identity of the calling station should be announced.

When the operator'at the master station replies to station A,`key a should'be operated before key T is restored to normal. This is desirable since, if key a is operated after key T, the howling signal is again transmitted to station A by the operation of key a. Relay 4 is operated immediately since relay 5 is already actuated vas before described.

Additional Vstations such as station YB, etc., Y

may be provided which may be commun1- cated with from the master stationfin the same manner as station A, by operating the corresponding keyb, etc. Y x v Key M is used when it is desired to'communicate with 'all stations simultaneously. Operating key M,`as will be seen Vbyreferring to the drawing, performs the functions of keys a, 1)etc., by virtueof the fact that allthe left spring contacts of keystt, b,fetc., are strapped tog therland connected to right spring contact'rof'key M. Y,

`The current is supplied Vto the system by a common battery located at the master station. The positive ypole of thefvbattery is grounded and foruniformity-the current'has beendescribed as I'fiowingfrom'negative p ole toV positive pole in vthe external circuits.

Condenser 29 is shunted across the armature and contact of buzzer 1 toy prevent* sparking at the contact What is claimed is: Y ,Y '4.1. A telephone systemcomprising ya .plu-

points.' ,n

signal any upon the operation oflsaidjslow-acting relay,

to release isaid slow acting relay, and a third relay, second relay and release of the said'slow- ,acting relay, to disconnect said source of signaling current and establish a Vtalking connection between first saidstation" and said other station.

2. Aftelephone system Icomprisin .a plurality of stations, Aa source ofsignaingcui:

rent, means atone offsaid Stations for seE lectively connecting said source one `of saidrother stations, and la chain` of cycli'cally' operating electromagnetic' relays,

rrality of stations, a source of slgnalingjcur-T stations for selecenergized'upon operation of the said to signal any A consisting of a Slow-acting relay, a second relay operative upon operation of said slowacting relay, to release said slow-acting relay and establish connections whereby said second relay remains operated, and a third relay, operative upon operation of the said second relay and the release of said slowacting relay, to disconnect said source of signaling current and establish a talking connection between first said station and said 10 other station.

In Witness whereof, I hereunto subscribe my name this 10th day of December, A. D. 1919.

CHARLES W. KECKLER. 

